This invention relates to circuitry used to operate an ionizable gas-filled device commonly known as a flash tube. Such circuitry provides operating parameters which enable a flash tube to be used as a heat source in applications which demand substantial accuracy and reproducibility.
One such application for circuitry of the type described involves analysis of a biological material such as blood serum. Though such an analysis can be accomplished through various techniques, one technique involves the use of a centrifuge characterized by a rotatable surface having a plurality of fixtures mounted about the periphery. A container, holding a blood serum sample and an appropriate reagent, is typically mounted on one of the fixtures so that, upon operation of the centrifuge, a constituent component of the material in the container is isolated for subsequent analysis. This technique is generally described in U.S. Pat. No. 4,632,908, the disclosure therein being incorporated herein by reference.
Analysis of the isolated constituent component of a sample of biological material is preferably conducted under carefully controlled conditions. Thus, immediately prior to analysis it is preferred that each sample of material to be analyzed be at substantially the same temperature. This presents a relatively difficult problem because these samples are not necessarily at the same temperature when they are mounted on the centrifuge. Moreover, material samples are often mounted on the centrifuge at different times, whereby those samples which have been mounted earlier in time have necessarily been subject to different temperature gradients than subsequently mounted samples.
Time is also of the essence in completing the analysis of these material samples. Thus, it would be highly advantageous if the proper conditions for conducting the analysis, including establishing the proper temperature conditions, could be achieved within a very short time, typically about two minutes. This goal is especially difficult to achieve when samples of different temperatures are being rotated in a centrifuge at the relatively rapid rate of about one revolution every 30 milliseconds.
One method for accomplishing this task is by using a flash tube, positioned adjacent the periphery of the centrifuge, as a heat source. The flash tube, operating under the control of a microprocessor, can be made to provide bursts of radiant energy, i.e., heat, to selected samples of material to be analyzed as they rotate past the tube. Though this concept has been generally disclosed in the above-mentioned U.S. Pat. No. 4,632,908, the desire to operate the flash tube to achieve optimum results warranted further effort and investigation.
It is thus an object of the present invention to provide improved circuitry for operating a flash tube under conditions which would make it especially useful as a heat source to selectively heat various samples of material to be analyzed as such samples are rotated past the flash tube at a relatively rapid rate.
It is another object of this invention to provide an improved method for applying predetermined amounts of heat at predetermined times to various samples of biological materials under analysis.
It is a further object of this invention to provide improved instrumentation for conducting an analysis of biological material utilizing a centrifuge having a rotatable surface, a plurality of fixtures disposed about the periphery of the surface, a container mounted to at least one of the fixtures holding the material to be analyzed, computer means monitoring the rotation of the centrifuge for producing a position signal when the selected fixture is in a predetermined position, and circuitry, including a flash tube, for heating the material as it is rotated on the centrifuge.
Other objects, features and advantages of this invention will be apparent upon reading the detailed description of the invention summarized below.